Luna has been keeping her powers a secret from other people. One day, she initiates a fire in her house for being distracted, and is there when she comes to know that she's actually a witch. after that, She's summoned by her grandmother and goes to an island to train as a witch... a story about a modern witch and werewolf is about to begin.
Original Webtoon
http://www.comico.com.tw/articleList.nhn?titleNo=1207